A crop sprayer is an agricultural application machine that breaks up a liquid into droplets that are blown or ejected into the air for distributed application to a wide area. Sprayers are typically used to apply liquid solutions such as herbicides, fungicides, pesticides, fertilizers, and other chemical treatments to agricultural crops. A typical crop sprayer includes a large volume tank carried on a chassis. Such a crop sprayer can be traded behind a tractor or provided as a self-propelled unit having an integral cab and engine to move across fields of crops. Some crop sprayers include an extending boom that provides a transverse line of uniformly spaced spray nozzles connected by pipes to the tank.
Generally, the chemical to be sprayed is held in a tank. The shape of the tank may be constrained by the need to easily clean its interior of residual chemicals. A large volume capacity is desirable to prevent the need to leave the field to replenish the supply of chemicals. Thus, conventional crop sprayer machines often sport large and cumbersome tanks, which may become contaminated with a chemical solution. Multiple rinse liquids may be required to clean the inside of the tanks.
One approach to address this problem is the use of a tank that holds only fresh water, rather than a chemical solution. A water tank does not need to be thoroughly cleaned inside; thus, it may possess a shape that allows the entire crop sprayer machine to have a more compact configuration. However, if the main tank solely is used for water, a chemical recirculation or recovery system is generally not possible. Thus, a machine equipped with chemical injection units typically also uses the main tank for a chemical spray mix and therefore becomes contaminated with a chemical solution.